Improvement in screw-propellers



H. G. COOK & E. W. BARKER.

SCREW-PROPELLERS.

No. 170,937. Patented Dec.14, 1875.

UNITED STATES PATENT Orrron,

HORATIO G. COOK AND EZEKIEL W. BARKER, OF PORTLAND, MAINE.

IMPROVEMENT IN SCREW-PROPELLERS.

Specification forming part of Letters Patent No. 170,937, dated December14, 1875; application filed August 19, 1875.

To all whom tt may concern:

Be it known that we, HORATIO G. 000K and EZEKIEL W. BARKER, both ofPortland, in the county of Cumberland and State of Maine, have inventedcertain new and useful Improvements in PropellerWheels; and We do herebydeclare that the following is a full, clear, and exact descriptionthereof, which will enable others skilled in the art to which itpertains to make and use the same, reference being had to theaccompanying drawings and to the letters of reference marked thereon,which form a part of this specification.

Figure l is a front view. Fig. 2 is a detail to show the flanges at theouter end of each blade. Fig. 3 is a detail view of the shaft, showingthe arrangement of the blades. Fig. 4 is a detail view, sbowin g thearrangement of the flange on the blades.

Same letters show like parts.

In the class of devices to which this invention belongs various methodsof construction and arrangement have been used to render the blades moreefficient in use, and to this end the several blades have sometimes beenarranged one after or behind another on the propeller-shaft; or, inother cases, the ends of the blades have been provided with flanges onone side, or with angular flanges in the front and rear.

In our invention we have endeavored to perfect and utilize, by someessential changes in construction, both of these expedients in a singlepropeller; and to this end my said invention consists in suchconstruction, combination, and arrangement of blades attached toindividual sockets, and having at their outer ends flanges of uniform ornearly uniform width from end to end, projecting over the front andrear, that said blades shall be situated one behind the other, whereby avery eflicient device is produced, all as will now be more specificallyand in detail set out and explained.

The arrangement of the blades A is indicated in Fig. 2, where are shownthe several sleeves or sockets a, fitting around the shaft B, andrigidly attached thereto, each of which sleeves carries one of theblades of the propeller. This disposition of the blades increases theirpropelling power. The arrangement of the flange is shown in Fig. 3 andFig. 4., which are intended to show the flange a, a, on the outer end ofthe blade, at nearly right angles to the plane of the same, andprojecting more over the rear than the front face thereof.

When the wheel is in operation the effect of this flange is to hold thewater and prevent it from flowing freely away from the blades. Thewater, being thus to an extent confined or held stationary, affords tothe blades a more fixed substance upon which to act, and thus enablesthe blades to transmit an increased power or force to the part morespeed to the vessel from the same number and velocity of revolutionsthan they would do if the water were not thus held and confined. Thesmaller flange on the front of the blades aids in backing.

The arrangement of the blades upon the shaft and the flanges incombination greatly improves the power of the propeller, because thearrangement of the blades gives each one its own water, and enables theflanges to the same to act undisturbed by the action of the otherblades.

Any number of blades may be employed, and any desired pitch orinclination given to the blades.

What we claim as our invention, and desire to secure by Letters Patent,is-

In the propeller-wheel herein described, the combination of blades A A,attached to the shaft one after the other, each upon its individualsocket, and each having at its outer end flanges a a, of uniform ornearly uniform width from end to end, projecting front and rear,substantially as and for the purposes set forth.

In testimony that we claim the foregoing as our own we affix oursignatures in presence of two witnesses.

H. G. OOOK. EZEKIEL W. BARKER.

Witnesses:

CHARLES E. CLIFFORD, FRANK H. JORDAN.

shaft, and thus to im-

